Corrugated and paperboard containers are made from pieces of flat stock that are typically die cut into shapes that define various panels. The shapes are folded along strategic lines between the panels, and at least one overlapping strip or panel is typically glued, taped or otherwise affixed to another panel to form a closed perimeter. The various panels are intended to become the walls, top and/or bottom of a full or partial enclosure when folded into place. Often, the containers are supplied in a collapsed or flattened parallelogram state (known as knocked-down-flat or “KDF”), for efficient storage, handling and shipping. Before packing, the containers are opened out into a hollow form and the panels are folded to reside in orthogonal planes.
Such containers can be more or less complicated. A simple version known as the regular slotted carton (RSC) has four side walls, each of which has a top and bottom flap. More complicated versions have doubled-over panels, reinforcing folded parts, inter-engaging tabs and slots and other features.
Such containers advantageously are produced by feeding flat integral die cut sheets through a fold-and-glue machine, such as those available from Bobst Group, Inc. of Roseland, N.J., to apply adhesive and preliminarily to fold over select panels so that the panels are adhered in a KDF state for shipping or storage, ready to be erected into their final configuration by articulating the panels around adjoining folds. A simple RSC version is erected by pressing inwardly from diagonally opposite corners and folding the flaps inwardly by 90° from their adjoined panels. In relatively more complicated full or partial containers, various panels may need to be folded in appropriate directions in appropriate order. Various tabs may need to be inserted into respective slots and so forth.
Containers as described can be used for displaying items or goods for the consumers at the point-of-sale location. Minimizing the effort and complication required to erect and set up the containers is an important factor for the viability and success of the particular container design. Thus, the number of parts required to erect or assemble the containers from their KDF configuration is an important element in the acceptability of the container design.
Generally, a container design is most efficient if most or all of its panels, tabs and other parts are integral panels and extensions of panels cut from a single flat blank, i.e., integral parts of the same sheet of material. Separate discrete parts such as separate lids, inserted partitions, shelves, reinforcing inserts and the like require attention to inventory, manual assembly steps and other complications during the production, erection and set up of the container. Separate parts are not desirable.
For these reasons, conventional KDF-type containers routinely are provided in a single piece flat blanks wherein all the panels necessary to construct or erect a container are members of a single sheet of stock material, cut out along an outline and scored or perforated at fold lines so as to provide all the necessary parts in an integral unit. The various seams are glued and the various folding connections between panels are cut, scored, compressed, etc.
The die cut integral blanks, preferably preliminarily weakened along prospective fold lines, are processed through the fold and glue machine. Glue is applied at preselected surfaces that are to overlap at seams. Panels are folded around fold joints. The KDF container blanks are thus produced and assembled in a state ready to be packed and shipped. For more complicated container designs, for example including lids or inserts, the KDF container blanks may be accompanied by separate discrete parts, but they add cost and require time for inventory attention, assembly and other reasons.
Because conventional KDF containers preferably are integral sheets, the panel layout design and general container complexity are limited. There is a need for ways to permit container designs to be made into complex structures, but without entailing complex parts and extensive assembly steps.